Scientists have linked more than 800 genes to autism spectrum disorder, making a one-size-fits-all medication difficult to find.
But now, researchers at Yale University say they may have cracked the code for some patients — and could treat them using a common prescription medication.
In a study, the team screened 774 FDA-approved drugs to find out how they impacted the behavior of zebrafish that were genetically modified to have autism.
The analysis revealed that one drug, levocarnitine, sold under the brand name Carnitor, boosted how the fish interpreted and responded to their environment, processes autistic people can struggle with.
The 44-cent-a-pill drug, available only with a prescription, is currently used to treat a rare genetic condition called carnitine deficiency, where the body has too little carnitine — a vital energy substance for cells — and by athletes seeking to boost their performance by giving their cells more energy. Nearly 400,000 prescriptions for levocarnitine are written nationwide every year.
It was not clear exactly how the drug helped to reverse autism symptoms, but scientists said it may be helping to boost energy production in regions of the brain that have low activity in some autistic people, such as those linked to language or emotion.
Dr Ellen Hoffman, a neurobiologist who led the research, said: ‘Because autism spectrum disorder is highly clinically and genetically [varied], it is challenging to identify drug candidates.
‘Our study highlights the importance of [analyzing] autism risk genes to identify potential [treatments].’
Scientists behind a new study say they may have found a new drug that could treat certain behaviors of autism (stock image)
The scientists said the results were promising, although they urged patients not to purchase and start taking the drug for autism. They noted the results needed to be confirmed in human trials, which can take several years.
In their study, the zebrafish had their DNA edited to carry two specific genes linked to autism — SCN2A and DYRK1A. Studies suggest only up to 0.5 percent of autism sufferers carry at least one of these genes, an important limitation of the research.
The findings come as autism rates have surged in America, with an estimated one in 31 children now diagnosed with the condition compared to one in 150 in 2000. Overall, 5.4 million Americans are estimated to be living with autism.
It isn’t clear what’s behind the explosion in cases, but experts have blamed increased awareness and the expansion of the definition of the condition to include other milder cases of communication problems.
There is currently no cure for autism, but scientists are constantly working on new treatments to alleviate severe symptoms such as being nonverbal.
Levocarnitine is primarily used to treat the disorder carnitine deficiency, which affects anywhere from one in 40,000 to one in 140,000 newborns in the US.
Carnitine is a natural substance that the body uses to process fats and produce energy, which is normally acquired from consuming foods. In carnitine deficiency, sufferers have a mutation that leaves them struggling to transport the substance into cells.
In the study, published in the Proceedings of the National Academy of Sciences, the team first exposed non-gene-edited zebrafish — which share 70 percent of their DNA with humans — to the FDA-approved drugs.
Other drugs that were tested include estropipate, sold under the brand name Ogen, a prescription drug used to treat menopause symptoms, and paclitaxel, also known as Taxol, which is a cancer medication.
After observing their response, scientists identified 520 drugs that were not toxic to the fish and had a significant impact on their behavior.
The fish were then gene-edited to add DNA linked to autism.
At the larval stage, between 24 and 72 hours old, the gene-edited fish were then re-exposed to these drugs in the lab. Scientists monitored the fish for their reaction to changes in the environment while being exposed to the drug.
Human stem cells were then exposed to the drugs to confirm that they were safe to use in humans.
The team found levocarnitine had the strongest ability to suppress both DNA mutations.
The researchers have published their results in an online database, and hope that the data will be used to investigate new treatments for autism.
They are now considering human clinical trials testing levocarnitine.
Asked whether patients should start taking levocarnitine to treat autism, the researchers said: ‘Not yet.
‘While the results in fish and human stem cells are incredibly promising, this study provides the “groundwork” for clinical trials.’
